Al₂O₃@SiO₂ core–shell catalysts were synthesized by sol–gel method. The core size’control was provided by using of polyethylene glycol (PEG) and glycerol. The shell thickness was optimized by using the different amount of tetraethylorthosilicate (TEOS). The formation of core and shell structures in catalysts was seen in high resolution transmission electron microscopy (HRTEM) images. In some catalysts, the use of PEG caused to formation of a more monodisperse core structure. The particle size of catalysts was observed in the range of 8–12 nm. The BET (Brunauer–Emmett–Teller) surface area and total pore volume of catalysts ranged 440–1014 m²/g and 1.28–2.57 cm³/g, respectively. In addition, pore diameter reached up to 25 nm. The use of PEG and glycerol improved textural properties. While BET surface area and total pore volume values decreased by the increase of TEOS amount, shell thickness increased a little. Fourier transform infrared (FTIR) spectrums of the pyridine adsorbed catalysts revealed the presence of Lewis and Brønsted acid sites in the catalysts. The catalysts were tested in the degradation of polylactic acid (PLA) by using thermogravimetric analysis (TGA) technique. TGA results showed the degradation temperature of PLA decreased from 353 to 321 °C in the presence of catalysts. Activation energy values were calculated using Flynn–Wall–Ozawa method. The activation energy was reduced from 337 to 199 kJ/mol. Pore structure, particle size and acidity of catalysts significantly affected the degradation performance.

Al ₂ O ₃ @SiO ₂核壳催化剂是通过溶胶-凝胶法合成的。通过使用聚乙二醇（PEG）和甘油来提供核尺寸控制。通过使用不同量的原硅酸四乙酯（TEOS）优化壳厚度。在高分辨率透射电子显微镜（HRTEM）图像中可以看到催化剂中核和壳结构的形成。在某些催化剂中，PEG的使用导致形成更单分散的核结构。观察到催化剂的粒径在8–12 nm范围内。BET的表面积（Brunauer–Emmett–Teller）和总孔体积为440–1014 m ² / g和1.28–2.57 cm ³/ g。另外，孔径达到25nm。PEG和甘油的使用改善了质地特性。尽管BET表面积和总孔体积值随着TEOS量的增加而降低，但壳的厚度却有所增加。吡啶吸附的催化剂的傅立叶变换红外光谱（FTIR）揭示了催化剂中存在Lewis和Brønsted酸位。使用热重分析（TGA）技术测试了催化剂在聚乳酸（PLA）降解中的作用。TGA结果表明，在催化剂存在下，PLA的降解温度从353降低到321°C。活化能值是使用Flynn-Wall-Ozawa方法计算的。活化能从337降低到199 kJ / mol。孔结构